Conventionally, there is a known food heating device in which a food is heated while the food is being conveyed by an endless belt member. Examples of such conventional device include a device described in PTL 1. In the device described in PTL 1, the hot air is generated by a hot air generating device, and the generated hot air is sent to a single-graining device through a hot air duct. A hot air flow is generated by an exhaust fan so that the hot air uniformly flows through the mesh of a net conveyor from an upper side toward a lower side. The hot air is blown to the food moving on the net conveyor, so that the food is dried.